Lock



FIG. 1 is a front perspective view of a lock showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a left side view thereof.

The broken lines, which define the bounds of the claimed design, form no part thereof. The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

I claim the ornamental design for a lock, as shown and described. 